C语言:键入n(0<n<10,错误提示并退出),求1,121,12321,1234321,…第n项...答:);fun(n,i+1);} return;} int main(int argc,char *argv[]){ int n;printf("Enter n(int 0<n<10)...\nn=");if(scanf("%d",&n)==1 && n>0 && n<10){ printf("Item%d is ",n);fun(n,1);putchar('\n');} else puts("Input error, exit...");return 0;} ...